The only real option is too keep the area free of debris. If this is your tree, just clean out the crotch every few weeks. Trees are not as susceptable as one would believe. I cabled a hemlock a few months ago with the same problem.
After I climbed up I realized the more I tightened the cable to more sway between the leaders. I could actually pull on the cable and move both trees.
To say the least, I was out of the tree in no time, and then cut it down. The root system was so decayed that as I PUSHED the butt over there was almost no resistance and the whole root flare pulled out of the ground.
We know alot about trees but the scary part is no matter how safe you are sometimes there is no way of saving a tree. I am soooo excited the tree did not fall while I was tied into it.